Dispatching system



July 23, 1935. H. E. HERSHEY ET AL 2,008,910

DISPATCHING SYSTEM Filed July 15, 1931 8 Sheets-Sheet l CUSTOMERS REL/1Y5 Imrsn ur's- Har'r' Hzrs I E H HZfrl H. Bllliunu July 23, 1935. H. E. HERSHEY El" AL DISPATCHING SYSTEM was . B x mm N m3 3 E Ham" H271 W14 July 23, 1935. E HEY ET AL 2,008,910

DISPATCHING SYSTEM Filed July 13, 1931 8 Sheets-Sheet 3 T0 FEECEEDING .srnmw AND ro D/JPATCHER i IQ v 8% gm 3m Gm July 23, 1935. H. E. HERSHEY ET AL DISPATCHING SYSTEM 8 Sheets-Sheet 4 Filed July 13, 1931 is W QR HIIIHI .llllllll Inuln are 1" EHlrlZie c1 H.5IZZLUI H12" HUN ul llllL July 23, 1935. H. E. HERSHEY ET AL DISPATCHING SYSTEM Filed July 13, 1931 8 Sheets-Sheet 5 EORQMQQQU hwwtk .53 kwkm anti 2 a: zmEmm wmm Irwin are HIT'I" EHarsha Hb'ruld HEaniuiiE WWW J1EE,

July 23, 1935. H. E. HERSHEY El AL 2,003,910

DISPATCHING SYSTEM Filed July 13, 1951 8 Sheets-Sheet 6 Q 1% Wm Ri www nLlulllL. Q M wk G 3 3 Wm Q? 4 a? g? \g EQE w Esq- Patented July 23, 1935 UNITED s..TAT Es TEN O I E" Application my 13,'1931,SeriaiNo. 550 :;v v Y GClaims. (01.171453) The present invention relates in general to dispatching systems, butis particularly concerned in the provision of a dispatching system in which any number of field stations'may be intercon- 5 nected, by. means ofa single pair of line conductors, to a dlspatchers station.

Among the objects of the invention are, to provide a relatively simplesystem of circuits and apparatus, whereby a dispatcher may selectively perform operations in any field station, and wherein as a result thereof, apparatus at such' field station will automatically send in a return indication to advise the disp'atcherthat the desired function has been performed. 1

Other features and objects comprise the provision of mea-nsforeflectively locking out all other field stations and the dispatchers station while any field station of the systemis transmitting. an indication to the dispatchers station, and for likewise looking out all field stations from interfering with the transmission of a control signal from the dispatchers station.

Still other features have to do with the provision of ineans for cutting out any station without-affecting. the remaining stations, and in the provision of circuits and apparatus enabling any field station'to become the last station of the system.

.The invention isz illustrated'in eight figm'es of drawings. ranged-with Fig. 1 immediately above Fig. 2 and with Figs. 3 and '4 to the right of Figs. 2 and 1,

respectively, diagrammatically illustrate the apparatusand circuits of one field station of the system.

TheFigs. 5 to 8, inclusive, when arranged with Fig. 5 immediately above Fig. 6 and'with Figs. 7 and 8 placed at the right of Figs. 6 and 5,-respectively, diagrammatically illustrate the circuitsand apparatus of the dispatchers station of the system. i

-The tell-tale relays, the relays of the miscellaneous relay .group, and sender and connector relays are of the general'type ordinarily employed in automatic telephone systems. The polar relays are of the stay-puttypeythat is, their armatures always remain in their last opera-ted position. w v

The senderswitches S and 'SS' areof thewell known single motion pawl and ratchettype, arranged to advance their wipers upon each deenergization of their motor magnet.

The mechanisms of the incoming selector switch IS andof the connector seizing'switch CS are also of the wellknown single motion pawl Figs. -1 to 4 inclusive,- when are and ratchet type, but differ from the sender switchesln that they'always advance their wipers upon the energization of their motor magnet, and are provided with release magnets which function, when energized, to permit their-wipers 5 to restore under tension of their restoring springs. e

' The connector switches D and D, employed to select the polar relays, are of the well known Strowger type. i r

The relay I00 and the other like relays, included in the interrupted dash-line rectangles of Fig. l are merely shown to make the disclosureof applicants invention complete. 'They have been labeled "Customers" relays on the assumption of sale of the equipment covered by the present invention to a customer'already having these relays and the customers equipment hereinafter referredto. i j

It is believed that a most thorough understanclingot the invention can be obtained by describ ing the operation of the'system.

Referring now particularly to the field station circuitsand apparatus.comprising Figs. 1 to 4; it is assumed that all switchesare at normal, and that all of the relays in the field-station are in the position shown. I

The tell-tale relay illiis energized and locked by way of the-upper contacts of the customer's relay I00, because of a previous operation. The relay 201 of themiscellaneous-relay groupis energized because it ls'the line relay for this station and is included in a normally closed line including all-statlons'of the system, This circuit'may be traced from the positive side of the line battery at the dispatchers board, Fig. 5, through'the dispatchers line relay 601', the lower break contacts of relays 615 and Gliljrespectively, #1 line conductor extendingto-the-field station, through contacts of the station cut-out switch S'l, through 40 the winding of the field'line relay Mil, and out over #iline, throughtheline relaysof the succeeding field statlons,- not shown, and backover #2 line, through the st'atio'ncut-out switch SI, the inner-lower break contacts of relay Zlll, the switch SI and theta line to negative potential at the 'dispatcher's "station. The polar relays -P and P "are magnetically held in' the position shown; because that happens to be their last opelated-position. 1 H

, Tell-talerelay operation Itwill now'be' assumed that thearmature of the customer's relay ill moves to itslower'positlon. I

The relay H0 becomes deenergized, because of the opening of its circuit which, as previously stated included the upper contact 01' the customer's relay I00. The deenergization of relay-H0, is however without eil'ect at this time. The relay H0 becomes energized over the circuit extending from positive potential supplied through the lower contacts of the customer's relay I00, the break contacts oi relay I I0, the inner-upper break contacts of relay H0, the winding of this relay, its lower break contacts, pick-up conductor 220, and through the break contacts oi relay 20l and the upper break contacts of relay 202 to negative potential. The relay H0, upon operating, completes a locking circuit for itself which includes the winding of relay 20 l conductor 222, the upper break contacts of relay 202 to negative potential.-

The relay 2!, accordingly, operates and at its upper contacts removes negative potential from the tell-tale pick-up conductor 220. Thetell-tale relay H0 also, at its three lowermost contact sets connects positive potential to the conductors I30, I31, and I00. These conductors, obviously, extend by way oi. the cross-connecting frame 000, and by way of appropriate jumpers thereat to the first, third, and fourth bank contacts, respectively, of the first, second, and third-digit banks III, 352, and 053, thereby marking the codes on the sender so that the same will subsequently trans: mit the code I34 to the line. Furthermore, the relay H8 at its inner-lower make contacts prepares the reset circuit of relay 0.

Miscellaneous relay operation The relay 20 l in addition to breaking the pickup circuit for the tell-tale relay, at its lower con:- tacts completes the circuit of relay 200 by way or the upper resting contacts of relay 209. The relay 205, upon energizing, vibrates its armature which eventually comes to restin energizedposition, and closes the circuit of slow-to-pull relay 200. The slow-acting characteristic of relays 200 and 206 may be adjusted to introduces delay anywhere irom one-tenth second to two seconds. The purpose of this. delay'is to provide the necessary interval between codes ior the release of the connector at thedispatchcr's station. In other words, the time between the reenergization of the line relay 201 at the end 0! a code and its deenergization for the beginningof the postcode must be suflicient to allow for the complete release oi" the distant Strowger switch. r

The relay 200, upon energizing, closes a circuit, by way or the lower breakcontacts of relay 200, to the relay 2". This latter, relay, upon operating at its middle-lower contacts opens the #1 line, at its inner-lower contacts transters the #2 line in from the #2 line "out? to the "out side of the line relay; 201, ,thereby removingline battery from all stations more distant from the dispatchers station, at its lowermost contacts prepares its own locking circuit, at its upper-outer make contacts closes a. point in the circuits to relays 2 and 211 and in the locking circuit for relay 210, and at its inner-upper contacts opens the operate ,lead 220 extending to the switches CS and D and closes a point in the operating circuit of relay 2".

The opening of the #1 line causes the deepergization of the line relay 201, which, at its back contacts completes the circuit of slow-release relay 200 which, in turn, completes the circuit of slow-release relay 200. Upon the energization of relay 200 this relay, at its lowermost contacts opens the operating circuit or relay 2" and completes a locking circuit for this relay which includes the conductors 220 and 224 and the break contacts of the relay ill of the sender switch BS. The relay 200 also, at its upper make contacts completes a circuit by way of the upper-outer make contacts'ot relay 210 to the relay 210, and by way 01' the break contacts of relay 210 through the winding of relay 211. The relays 2 l0 and III also operate consequent to the operation oi relay 2", but without eiiect at this time. The relay 200 also, at its upper contacts opens the operating circuit oi relay 200, which in turn opens the circuit of relay 200, and at its larger-upper contacts disconnects the conductor The relay 1, upon energizing, closes the circuit of relay 2" which also operates, and closes a circuit which extends from the #I line in, conductor 220, through the lower contacts of relay 210,.the line relay 201, compensating resistance 220, the inner-lower contacts of relay 2I0 to the line #2 in". The line relay 201, accordingly, energizes, and at its front contacts completes the prepared circuit of relay 2" by way 0!, the inner-upp r. make contacts of relay 200 and the inner-upper make contacts 01' relay H0. The relay 210, according y. energizes and locks itseli'up by way of its upper contacts, the upper make contacts of relay 210 and positive potential at the upper make contacts of relay 200. The relay 2" also, stits lower contacts interrupts the circuit of relay 2", which in turn opens the circuit of relay 210. The latter relay releases quickly and again opens the circuit of the line relay 201.

The relays 2H and H2 provide a delay feature which constitutes part of the. lookout circuit, and which will be goneinto later. Ordinarily the relay 212 does not have time to operate beiore the relay'l II has again released.

The foregoing operation or relays. 211, 2| 0, and H0 have thus resulted in a single pulse, of approximately two-tenth seconds duration, being delivered vto all or the line relays 201 of the field stations lying between the active field station and the dispatcher's station. This is termed the preliminary pulse, which has three functions, the first being thecornpletionot the seizure of the line by this station.- The second function is the lockingyout oi the connectors of all iield stations between this station and the dispatcher's station, so that these latter connectors will not step on the codes transmitted from the held. The third function is the preparation oi the dispzltcher's connector for receiving a code from the ii (1. j, c

The relay 210, upon energizing as before explained, at its upper contacts completes a locking circuit for itself including the upper contacts of relay 210 and the upper make contacts 01' relay 200; torestalls the operation of relay 2l2by at its lower contacts opening the circuit oi relay 211, with the resultant opening vot the circuit of relay 210, and extendsposltive potential through its lower make. contacts and conductor 200, to the relay 000 oi the sender. The relay 000, accordly. also energizes. 7

. The function of delay relays ml'snd as of the sendenis to allow a suitable interval, after the preliminaryipulse, tor the completion of all lockout functions, and forthe preparation of the dispatchers incoming circuit;

Relay 305, upon'energizing, completes the circuit of relay 306. This relay, upon energizing; at

its middle-upper contacts closes a circuit for the impulsing relay 302 by way of the upper break contacts of relay 308 and the lower break contacts of pulsing relay 30|, at its lower contacts prepares the locking circuit of relays 3|2 to 315, inclusive, at its inner-upper contacts prepares a locking circuit for relay 301, and at its upperouter contacts prepares the homing circuit for the sender switch SS.

The completion of the aforementioned circuit of pulsing relay 302 causes this latter relay to energize. The relay 302 at its inner-upper contacts completes the circuit of-relay 303 andat its upper contacts completes a locking circuit for itself by way of the break contacts of relay 30l. The relay 303, upon'operating, at its inner-upper contacts completes the circuit of relay 30| which,'in turn,- opens the circuit of relay 302. The relays MI, 302, and 303, accordingly, interact so long as there is positivepotentlal supplied through the inner-upper contacts of the relay 308. Each time the relay 303 energizes, in addition to'closing thecircuit of the relay 30|, at its lowermost contacts it transmits pulses from negative potential on the #2 in line, supplied from the dispatchers station, through the inner-lower make contacts of relay 2|0, the compensating resistance 225, line relay 201, conductor 226, through the lower break contacts of relay 308, through the lower make contacts of relay 303, and conductor 228 to the line #I "in", and through the line relays of any field stations intermediate to the sending field station and the dispatchers.

station, and'through the line relay 001 of the dispatchers station by way of the lower break contacts of relay 8|0 and the lower break contacts of relay 6|5 to positive potential; These pulses operate the associated line relay of the intermediate stations and of the dispatchers station, which, in turn, through the medium of their resting contacts maintain their associated slowrelease relays, such as 208 and 208, energized because 01 their slow-to-release characteristic.

The relay 303 at its upper contacts transmits pulses direct to the motor magnet 33| of the sender switch, causing the latter ,to take one step for each pulsedelivered into the #I line.

At the first step of the sender switch, the offnormal springs ON close, thereby causing the energization of the slow-release relay 308 which, in turn, completes the circuit of relay 3|0 and it in turn, the circuit of relay 3| The relay 3| l, upon operating, prepares a primary locking circuit for the relay 308.

When the marked contact is reached, positive potential is applied over the conductor I38 extending from the tell-tale relay 8, through the cross-connecting'frame, the first-digit bank 35| and its associated wiper, to the conductor 38l, and through the break contacts of relay 3 l2, and the winding of relay 308 to negative potential. The relay 308, upon energizing, at its lowermost contacts opens the'pulsing circuit to the #l line, at its upper break contacts, also opens the circuit extending to the pulsing relay 302, at its middle-upper contacts completes a locking circuit for itself and at its uppermost contacts completes the return-to-normal circuit for the sender, which extends from positive potential at the ofl-normal contacts ON, through the uppermost contacts of relay 308,'the uppermost contacts of 0N open and'stop the sender in this position.

The relay 308 also deenergizes consequent to the" opening of the off-normal contactsON. In the interval between thetime the wiper of the transfer bank 350 reaches its normal contact and the deenergization of relay 308, a circuit is closed from positive potential on the wiper of bank 350 in its normal position, through the lower make contacts of relay 308, the break contacts of relay 3|3, and the'winding of counting relay 3|2 to negative potential. The relay 3|2 at its lower contacts prepares the circuit of relay 3|3, and at its upper contacts transfers the control circuit of relay 308 from connection'with the conductor 36| and the associated first-digit bank 35| by way of the back contacts of relay 3| to the conductor 362 extending to the wiper of the second-digit bank 352 *As soonas the contacts of the relay 309 restore the relay 3|3 becomes energized in series with the relay 3|2 over thecircuit including the lower contacts of relay 308. Upon the energization of relay 3|3 this relay transfers the counting circuit from connection with relay 3|2 to the gilsay 3|! by way of the break contacts of relay Returningmto a consideration of the action of the off-normal springs ON, itwill be remembered that, the relay 308 deenergized shortly, after the sender returned to normal, thereby opening the circuit of theslow-release relay 3 0, which in turn opens the circuit of slow-release relay 3| The relay 3| |,upon deenergizing, at its contacts opens the locking circuit of relay 308 which, accordingly, deenergizes and causes the sender to transmit the second digit of the code. At this time the relay 308 is associated with the wiper of the second-digit bank 352, and when the marked contact is reached, positive potential is applied over the conductor I31 extending from the tell-tale relay ||8, throughthe cross-connecting frame, the third-bank contact of bank 352,, its associated wiper, the conductor 362, the break contacts of relay 3|, the upper working contacts of relay 3| 2, and the winding of code-cut-oil relay 308 to negative potential. The relay 308 will, accordingly, again operate as before to cut-off the pulses, and this time three pulses will have been delivered tothe#|line.f The sender switch will now return to normal, in the manner previously described, and when the same reaches normal the relays 3H and 3|5 will operate, in substantially the same manner as did relays 3|2 and 3|3 at the termination of the first code. The relay 3 transfers the circuit of the code cut-oil relay 308 from connection with the conductor 362 extending to the wiper of the second-digit bank 352 and connects it with the conductor 383 extending to the wiper oi the third-, digit bank 353. The relay 3|8, upon operating, at its upper contacts closes a point in thesecon dary locking circuit for relays 301' and 3|0, and at its lower contacts extends the counting circuit into connection with'the relay 3|8.

The sender switch will new function to send the third digit of the code, as soon as the 011?- normal springs ON havebecome operated, the relay 308 again becomes energized and at its lower contactscompletes the circuit of relay 301 by way of the upper contacts 01 the relay 3II. The relay 301, upon operating, at its contacts completes a locking circuit for itself and prepares the secondary locking circuitv or the relay 300, by extending its own locking circuit from the lower contacts of the relay 306 to the relay 3I0, thus making the relays 3I0 and 3| I, as well as the relay 308, independent of relay 300.

Since at this time the relay 300 is associated with the wiper oi the third-digit bank 353, when the marked contact is reached, relay 300 will operate as before to cut-oil the pulses and this time four such pulses will have been delivered to' the #I line.

The code is now completed, and the sender must not again function following the deener'gization of relay 309. For this reason, the relays 3I0, 3H, and 30I'have been locked up through the inner-upper contacts of relay 300, as previously described.

At the end ofthe transmission'of. the third digit, the relay 3I6 energizes over the previously traced counting circuit, at its innerelower make contacts completes a locking circuit for itself .including the lowermost contacts of the relay 300, at its lowermost contacts places positive potential upon the reset conductor 232 to the winding of reset relay 204, and at its break contacts opens the circuit of relay 2I0.

As'a resullt of the second function, the relay 204 of the miscellaneous relay group becomes energized. This relay at its lower contacts completes the circuit of relay 203 by way .of the lower break contacts of relay 202. The relay 203, accordingly, energizes and closes a point in the circuit of the relay 202. The relay 204 also places positive potential on the reset common conductor 260 of the tell-tale relays. This positive potential passes through the inner-lower closed make contacts of the relay H and holds the relay IIO energized independently of the circuit formerly completed for it at the upper contacts of the re-' lay 2 I3.

As a result of the third function of the relay 3I6, as previously mentioned, the locking circuit of the relay 2 I 0 of the miscellaneous relay group is opened. The relay 2 I 0, accordingly, at its upperinner contacts opens the circuit of relay 304 of the sender, whereupon this relay and the other relays of the sender return to normal; and at these same contacts opens the locking circuit of relay 2I6 which, accordingly, deenergizes. The relay 2 I 0 also, at its lowermost contacts opens its own locking circuit, at its middle-lower contacts recloses the #I line, but without efiect at this time, as the line is still open at the contacts of relay 2I5, and at the uppermost contacts opens the circuit of relay 2I3, and atv its inner-lower contacts opens the by-path'of the #2 line conductor and re-establishes this conductor to its normal condition.

The relay 2I3, upon deenergizing, opens the circuit of relay 2I4 and it, inturn, the circuit of relay 2| 5. The relay 2I5 deenergizes after a slight delay, at its upper contacts opensthe circuit of relay 202, and at its lower contacts closes the #I line, whereupon the line relay 201 will energize and open the circuit to the associated slow, release relay 208, which in turn, opens the circuit of slow-release relay 209. The station has thus released the line, which may now be seized by some other field station. 7

The slow-release relays 2I3, 2 I4, and 2I5 ailord the necessary delay required between the last digit of the code and the re-energization of the line relays for the last relay counting operation, in the dispatchers incoming selector.

Returning to a consideration of the release of the sender, mentioned heretofore as the first function or the release of relay 2| 0, the release of relay 304 of the sender causes the release of relay 305, which, in turn, opens the circuit of relay 306. This latter relay, at its middle-upper contacts, opens the circuit extending to the relay 302 of the pulsing relay group, at its uppermost contacts opens the homing circuit of the sender switch, at its lowermost contacts opens the locking circuit for, and causes the release of, the relays 301, and 3I2.to 3I6, inclusive, aswell as of the relay 3I0 which, in turn, opens the circuit of relay 3. This latter relay, upon deenergizing, opens the locking circuit of relay 308.

Second tell-tale relay operation Field connector lockout When the field station is sending, its connector is out of control of the pulse circuit, due to its operate conductor 229 being opened at the innerupper break contacts of its associated relay 2I0, as previously mentioned. On this account, neither the preliminary pulsing nor the code pulses have any eiiect on the connector. When a station beyond this station is sending, the line relay 201, in response to the preliminary pulse, opens the circuit by way of the inner-upper make contacts 01 relay 209 and the inner-upper break contacts of relay 2I0 to the operate conductor 229, and from thence by way of the break contacts of the relay 0, to point 420 where the circuit divides, one branch passing through the winding of the relay 40I to negative potential and the other branch extending by way of the lower-break contacts of relay 404, the break contacts of relay M2 to the winding of relay H I and negative potential. The relay 40I, upon operating, completes the'circuit of relay 402, which in turn at its upper contacts completes the circuit of relay 403 by way of the upper break contacts of relay 404. Upon the cessation of the preliminary pulse, the relay 4I2 becomes energized in series with the relay 4, these relays now being locked up by positive potential supplied to the hold conductor 225 at the upper-make contacts oi relay 209. After a slight interval following the termination of the preliminary pulse, the slow-release relays MI and 402 become deenergized. I The relay 402, upon deenergizing, at its upper contacts removes positive potential from the upper winding of relay 403 and from the winding of relay 404, the relay 404, accordingly, becomes energized in series with the relay 403 from positive potential supplied through the lower contacts or the relay M I. The relay 404, upon operating, at itslower contacts opens the operating circuit leading to the relays 4H and U3 and extendsthis operating circuit to the inner-lower contacts of the relay 4 I 4. This relay, however, has failed to energize, and continues to hold openthe operate circuit to the magnet Hi. It will thus be evident that the subsequent series of codepulses will be ineffective to operate the To explain thisoperation it is assumed that all switches are at normal, and that all relays are in theDOitionsshown. When the dispatcher seizes the line, all of the line, relays such as 201 of the miscellaneous relay group, will deenergize and close the circuit of relay 208'. This relay in turn closes the circuit of the relay 209 and to the conductor 228' extending to the wiper of the field connectorby way of the break contacts of the .relay .402 thereof. The relay 209, upon operating, at its lowerbreak contacts opens.

the circuit' of Irelay 2l0, at its upper make contacts places positive potential on the, hold I conductor 225 extending to the field connector,

and at its inner-upper contacts opens a point in the connector release circuit, and closes a point in the operate circuit of the field connector.

When the dispatcher moves the first operate key to its upper position, the code 10l is sent out. As will be explained, the preliminary digit 2, first precedes all codes'tothe field. The line relay 201, accordingly, responds to the preliminary digit 2, but the slowto-release relays 208 and 209, which pulled up upon the deenergization of the relay 201, will not fallaway during the momentary interruption in the circuit to relay 201. Therefore, at each operation of the line relay 201 a circuit is closed by way of the inner-upper 'make contacts of relay 209, the inner-up'perbreak contacts of relay M0, the operate conductor 229, upper break contacts of relay 4l0, and the relay 40! to negative potential. The relay 40l energizes upon the first pulse and will remain energized until shortly after the end of the second pulse. The relay 40I in turn completes a circuit for relay. 402 and it, in turn; completes the circuit of relay 403'by way of the upper break contacts of relay 404. The relay 403, upon energizing, prepares the circuit of relay 404. The first pulse to relay 40!, also extends by way of the lower break contacts of relay 404 and the break contacts of relay M2 to winding of relay 4| land negative potential. The relay 4| l, accordingly, also energizes and atits upper contacts prepares an operating circuit for relay 2, while at its lower contacts it applies holding potential to the common holding circuit for the relays 404 to H0, inclusive. Upon the cessation of theflrst pulse, relay 2 energizes in series with the relay 4| I over a circuit including the hold conductor 225 and positive potential supplied thereto at the upper make contacts of relay 209. The relay 4I2, upon operating, transfers the counting circuit from connection with relay 4 into connection with the relay 3, so that uponthe transmission of the second pulse of the preliminary digit it causesthe energization of the relay 4|3. Upon the cessation of the second pulse the'relay 4 becomes .energized in series with the relay 413 and at its upper contacts opens the counting circuit," while at its lower contacts it extends the operating circuit into connection with the magnet 4I5 of the conhector-seizing switch CS.

the

with the relay 403 and at its upper contacts opens the initial energizing circuit of relay 403 and prepares the energizing circuit of relay 405, while at its lower contacts it opens a point in the operate circuit'of relay 4 and. completes the extension'of'the operating circuit by way of the lower make contacts of relay M4 and the lower break contacts of relay 406 to the magnet 415 of theconnector-seizing switch CS.

The line relay 201 of the miscellaneous relay group will next respond to the seven impulses comprising the first digit of the code "I. The connector relays 4M and 402 will energize as before on the preliminary digit, and the relay 402 at its upper contact closes the circuit to the relay 405 by way of the upper make contacts of relay 404 and the upper break contacts of relay 406. At each operation of the line relay, a circuit is also closed by way of the lower make contacts of relay 404, the make contacts of relay 4, and through the lower break contacts of relay-406 to the winding of magnet 5 of the connectorseizing switch to negative potential.

As a result of the foregoing the connectorseizing switch advances its wiper to the seventh bank contact of its bank. At the end of the series of seven pulses, relays 4M and 402 again deenergize, whereby. the relay 405 locks up to the, hold conductor in series with the relay 406, which energizes over this circuit. This relay at its upper contacts transfers the counting circuit from connection with relay 405 into connection with relay 401, and at its lower contacts disconnects the operating circuit from connection with the magnet M5 and extends this circuit by'way of the wiper of the switch CS and the lower break contacts of the relay 408 'to the vertical magnet 4 l1 of the connector D. I

The next'series of impulses will accordingly pass through the vertical magnet 4" of the connector switch.. The relays 4M and 402 function as before to cause the operation at this time of counting relays 401 and the subsequent operation of relay 408 followingthe transmission of the second digit of the code. The relay 408, upon operating, at its lower contacts transfers the operating circuit from connection with the ver tical m net 1 into connection with the rotary magnet 8 of the seized connector, and at its upper contacts transfers the counting circuit to the relay 409'. The last series of impulses, this time comprising the digit I, will accordingly pass through-the rotary magnet H8 01' the connector. During the transmission of the last digit, relays 40! and 402 againfunction as before and the extended counting circuit causes the operation of the relay 409, followed by the operationofrelay 0 following the release of relay 402. The .relay 4| 0,'upon operating, at its upper contactsopens the oper-' ating circuit to. relay 401 and to the magnet 418, and at its lower contacts also opens the counting circuit. I

As' a result of the foregoing operations, the wiper 425 of the connector has been raised ten steps and rotated in one step and is now in engagement with the bank contact with which is associated the coil 428 of 'the first polar relay.

When the connector relay 402becomes deenergized, following the transmission of pulses to the rotary magnet 4l8 of the connector, the winding 426 of the first polarrelaywill be energized by positive potential supplied over the contacts of relay 208, wiper conductor 228', the break contacts of relay 402, wiper 425, the Cl contact of the connector bank, and the winding 426 of the first polar relay to negative potential. relay P will now move its armature over to the right to close certain circuits to the customer's relay while opening others.

The code to the field is now complete, and the dispatchers equipment will now maintain the line closed, thereby again energizing .all of the line relays in the system, whereupon all miscellaneous relays 208 and 209 and 608 and 609 will deenergize. The relay 209, upon deenergizing, completes the release circuit of its connector-seizing switch CS and of the associated connector, if the same has been operated. This circuit extends from positive potential supplied through the make contacts of the line relay 201, the inner-upper break contacts of slow-release relay 209, release conductor 228 and through the oil-normal-springs CNS and CNS of the switch CS and of the connector,

such as D, to the release magnets H6 and 420 of these switches to negative potential. Previous to the release of relays 208 and 209 the line relay 201 again places positive potential by way of the lower make contacts of relay 209 to the operate conductor 229, but this operation is without effect owing to the fact that the operate circult is at this, time open at the upper contacts of relay 4l0 of the connector.

The switch CS and the connector now return to normal, their release magnet circuits being opened at their off-normal contacts on the completion of the release operation. The relay 209 also, upon restoring its upper contacts removes positive potential from the hold conductor 225, whereupon all of the counting relays oi the field connector are restored. The switch CS at each field station has respondedfto the first digit, but

- the second and third digits will have been ineffective, except for such connectors whose pulsing circuits are ledthrough the seventh contacts of their switches CS, and only one of these will find a polar'relay coil connected to the bank contact Ol It should also be noted that the wiper of the connector switch is open during the time that the first field wiper 425 is passing over contacts'of a bank, because of the break contacts of relay l02, and is open during the release operation because of the deenergized condition of the relay 200.

Field lockout If the dispatcher is using the line, the field is lockedout because of the energized condition of miscellaneous relays 208 and 209 at all field stations. This is the case because, with the relay 209 energized, positive potential is removed from the lead extending through the break contacts oi! the relay 20l to the winding of relay 205. Therefore, no field station can seize, even though the miscellaneous relay 20! may be energized.

When a field station is using the line, all other field stations are locked out because of the same reason given aboveQi. e. they cannot establish a circuit for their relay 205, while the associated relays 208 and 209 are energized.

Simultaneous field operation Two field stations may function at so nearly the same time that their miscellaneous relays 2|0 become energized simultaneously. The station nearest to the dispatcher will function normally to seize the line, it being remembered that the relay 210 opens the line to all stations beyond it at its inner-lower break contacts. TIhe station beyond will lockout as follows:

The polar.

The line relay 201 will deenergize, and cause the deenergization of its associated relays 208 and 209. The relay 2l8 will attempt to send the preliminary pulse to the line relay in the usual manner, but its contacts will close without efiect, since the line is already open at the near field station, and relay 201 will not energize. Relay 2| O will remain energized, to maintain the circuit to relay 2 closed. In due time, therefore, the slow-to-pull'relay 2I2 will operate, and open the locking circuit of relay 2l0.

Relay 2 l will now fall away, andat its upper contacts opens the circuit of relays 213, 2, H8, 2| Land 2l2, respectively, and these relays also deenergize. The relays 205 and 206 have been previously deenergized upon the energization of relay 209, the station beyond is now locked out and all relays are again in their normal position, with the exception of the tell-tale relay andrelay 20l of the miscellaneous relay group, together with the line'relay 201 and its associated slow-release relays 208 and 209.

When the line is again freed, the energization of the line relay and the subsequent release of the associated relays 208 and 209 will again cause relays 205, 206, and H0 to test the line. If they are successful in causing the energization of relay 2l6 their task is done, and all other stations are now locked outuntil the now active field station has completed the transmission of the initiated'code.

Each field station is provided with a station cut-out switch Si which may be operated to cut that station out of the line without interiering with the other stations of the system. With a station cut-out, resistance X compensates for the resistance of the cut-out line relay'20l.

Each station is also provided with a last station switch S2 which may be operated to cut out all stations more distant from the dispatchers station. The resistance X of this switch compensates for the total resistance of the line relays oi' the field station cutoff the line.

Referring now to Figs. 5 to 8, inclusive, the

detailed circuit operations of the dispatchers station will be gone into. It is assumed that all of the switches and relays are in their normal position, as shown. Tell-tale relay H6 is energized becausethe lever spring of the first operate key is in its lower position. The miscellaneous relay 60! is energized because it isthe line relay. The first polar relay PI of the return indication polar relays has its armature magnetically held to the left because that hap pens to be its last operated position.

It will now be assumed that the dispatcher moves the lever of the first operate key to its upper position.

Tell-tale relay operation Relay BIG of the tell-tale relay group 'I'I'R will deenergize, but without efiect at this time. Relay 6l8 will energize over a circuit extending from negative potential supplied through the upper contacts of relay 602, through the upper break contacts of relay 60I, the pick-up conductor 620, through the lower break contacts of relay 6| 8, the.winding of relay lilB, its inner break contacts, and through the break contacts of relay 6I9 to positive potential supplied through the upper contact and first operate key. The relay 6i8, upon energizing, completes a locking circuit for itself extending from negative potential supplied through the upper contacts of relay 602,

the inner common lock-up conductor HI, the lower, make contacts of relay M0, the winding of this relay, its upper make contacts, through the upper break contacts of relay62l, and the conductor 622 and winding of relay G0! to positive potential. The locking up of relay 6| over the circuit just traced renders this relay independent of the first operate key, thus insuring that its code will be sent, even if the position. of the first operate key is again changed imme-i v diately. The. relay ,618 also, atits, inner-lower contacts prepares the, reset circuit for tell-talerelay GIS, and at its three lowermost sets of contacts applies marking potential to the conductors 636, 631, and -638 extending to the cross-connecting frame and then to bank'contacts of the .code sender. 1 Y

I Miscellaneousfrelay operation Relay 60I energizes over the traced locking circuit of tell-tale relay BIB and, at its inner-upper contacts, opens the pick-up circuit for all telltale relays corresponding to the, relay H8, so that no other such tell-tale relay can be operated until after a previously operated one has been restored. Relay 60| also, at its upper contacts completes the circuit of relay 605 by. way of the upper break contacts of relay 609. The relay 605,

upon operating, completes the circuit of relay: 606, which after an interval, in turn closes the circuit of relay 5H].

Relays 605 and 606 here again provide a delay feature to give the necessary interval between codes to insure the proper release of thefleld switches. CS andD. This function is necessary" only in case a number of codes are being sent in rapid sequence, as when the dispatcher operates several keys at once, or in rapid succession.

Relay 610, upon energizing, at its lower-outer contacts ,opens'the line, at its inner-lower con tacts prepares a locking circuit for itself, and at its uppercontacts completes the circuit of relays 6| i' and (H3. Relay 6|3, upon operating, closes thev circuit of relay 6M which, in turn,'.closes the circuit of relay 6L5. These relays, accordingly;

operate but their operation is without effect at this time. 1

Consequent to the openingxof the line, line relay 60! becomes deenergized and at its armature and back contact completes the circuit of slowrelease relay 608 which,.in turn, completes the circuit of relay 509. The relay 609, upon operating, atv its lower most contacts completes the locking circuit of relay 5l0. This circuit, includes'only conductor 623, the break' contacts of sender relay H8 and the conductor 624, and is;

therefore, independent of the contacts of relay 606. Relay 609, also, at its upperebre'ak contacts interrupts the circuit of relay 605,: which deenergizes and interrupts the circuit of relay 606, which also deenergizes at its upper make contact places positive potential upon the hold conductor 525 extending to the incoming selector IS, and

at its inner-upper break contacts opens a point in the circuit extending to the release conductor 626 and at these make contacts prepares-a circuit to the operate conductorifl; p

Returning to the consideration of the relay 0 ll ,WhlCl'l had its circuit; closed by the energiza The relay 6H after a delay,

closes a circuit over the sender start lead; 629 to the relay 704 of the sender. The relays 5H and pose of giving the dispatcher preference in case i of the simultaneous seizure of the line by the dispatcher and'held. 'This will be gone into more thoroughly in discussing the Dispatchers lockout.

Sender operation Relay 104 of thefsender now energizes and,

after a delay,-;.causes the energization of relay 105'. These delay relays 104 and 105 serve to further lengthen the-time interval between the opening of the line and the starting of the pulsing, mentioned in the last paragraph. Relay I05, upon operating, closes the circuit of relay 106 which accordingly energizes. This relay at its middle-upper contacts; closes a circuit by way of the inner-upper contactsof relay 108 and the contacts of relay I01 tothe relay 1020f the pulsing relays, at its outer-upper contacts prepares the return to normal circuit of the sender switch SS,-at its inner-lower contacts prepares the locking circuit for relay I01, and at its lower contacts prepares an operating and locking cirupon operating, interrupts the circuit of :relay 102 which, in turn, deenergizes and opens the circuits of relay 103. This action of these relays continues until subsequently cut-off; Relay 103,

accordingly, at its upper contacts sends impulses direct to 'the motor magnet "I of the sender switch, causing the latter to take one step for each pulse delivered to the line at the lowermost contacts of this relay. The pulses, whichare transmitted over the line, extend from positive potential on conductor 532, through the rheostat R milliameter M, #I line, through the line relay 601', c onductor'634, through-the lowermost contacts of relay 108, the lower contacts of pulsing relay 103, oonductor035, and over the. #1 line conductor out through the line relay of each field station, back over line conductor 2 to negative potential at the dispatchers station. These pulses will operate the line relay 601 of the miscellaneous relay group," but the slow-release relays'608 and 609' will remain energized during the momentary breaking of their circuits by the line relay. These pluses will also in a similar manner effect the line relay20'l and the associated relays 208 and 209 of the miscellaneous relay groups of all fieldstations.

At the first step of the sender switch off-normal springsONS thereof will close and cause the operation {of relays I09, H0, and 'H I. When the wiper of thepreliminary digit bank reaches its second bank contact, a circuit is closed from positive potential, through the bank contact and wiper fofthe bank 150, conductor I54ythe upper break contaots'of relay H2; and the winding of relay. 108 to negative potential. Relay I08 thereupon energizes and, at its lowermost contacts opens the traced pulsing circuit for the line relay60l, atits inner-upper con-. tacts interrupts the circuit extending to the pulsingv relay l02, at, its middle-upper make contacts completes a locking circuit for itself including the make contacts of relay II I, and at its upper-' most contacts completes the return-to-normal circuit of the sender. This circuitextends from SS, the

open the circuit to the motor magnet and to the Y slow-to-re1ease relay 109; Consequent to the deenergization of relay I09, relay H0, and in turn relay III becomes deenergized. Relay II I,-upon deenergizing, opens the locking circuit of relay I08 permitting it to restore. The slow-to-release relays I09, I I0, and II I, afford the necessary time interval between digits which is necessary to allow the relays 40I and 402 of-all field connectors to release and transfer the pulsing circuit. w

When the preliminaryv digit wiper of the bank I50 reaches its normal contacts, it closes a circuit to the countingrelay H3 as follows: from positive potential supplied through the contacts ofrelay II I, the middle-uppermake springs of relay I08, the upper break springs of relay II2, conductor I54, the wiper and normal bank contact I50, through the lower make contacts of relay I09 (relay I09 being slow-to-release has not yet released its armature), the lower break contacts of relay I I 2, and the winding of relay I I3 to nega tive potential. This circuit is opened an instant later when the relay I09 deenergizes, whereupon the relay II2 energizes in series with relay II3,'

andlocks to positive potential supplied through the lowermost contacts of relay I06.- The relay II2, upon energizing, atits uppermostcomtacts transfers the code-stop circuit from'the con-- ductor I54 extending to the wiper of bank I50 to.

the wiper of the first digit bank I5I by way of the upper break contacts of I relay H4 and conductor 'I6I,- and at its lower contacts opensthe 1 initial operating circuit of relay H3 and prepares the operating circuit'of relay H5.

The foregoing operation has resulted in the sending of two pulses out over theline'and through all of the line relays. This is termed the preliminary digit, which has two functions, the

first-being to lockout the. stepping circuit of the dispatcher's incoming selector,.and the second being to prepare the stepping circuit of the field connector. The second function-has already been discussed in the preceding description of the field station circuit under the heading To the field operation.

As to the first function, when the dispatchers line relay 601 energizes in response to the first extends through the relay, 80I to negative potential, while the other branch extends by way of the lower break contacts ofrelay 804 and the.

upper break contacts of relay M2 to the winding of relay 8 and negativepotential. Relay 80I energizes on the first pulse, and remains operated during the succeeding pulses due to its slow-release characteristic. This relay, closes the circuit of relay 802 which, in turn, causes the energization of the counting relay'808. The

counting relay 8 I I also energizes on the first pulse mination of the pulse, relay 8 I 4 energizes in series 1 with relay 8I3 and locks in turn to the hold conductor 625. Relay 8I4, upon operating, at its upper contactsopens the initial energizing circuit of relay 8I3, and at its lowercontacts opens the operate circuit extending to the motor mag-' net 8I5 of the incoming selector. At the termination of the second pulse, relay 80 I, after a slight delay, deenergizes and opens the circuit of relay 802. Upon' the release'of relay 802 the relay 804 becomes energized in series with the relay 803. The relay 804, upon operating, at its lowermost break contacts, opens a further point in the energizing circuit of relay 8I3.

Returning now to the'sender, when the relay 108 releases, as before explained, on the deenergization of relay III, the pulsing relays IOI, I02, and I03 and the sender switch again begin to function, to send the first digit of the code, which in this instance is 7.

When the wiper of the first digit bank I5I reachesthe seventh bank contact, a circuit is again closed through relay I08 as follows: from positive potential at the lowermost contacts of telltale relay 6 I8, conductor 636, and by way of cross connections on the cross-connecting frame I to the seventh contact of bank II, its associated wiper, conductor I6I, the upperbreak contacts of relay I I4, the upper make contacts of relay I I2, and the winding of relay I08 to negative potential. Relay I08, therefore, functions as before to open. the pulsing circuit and to restore the sender switch SS to normal position. When the sender switch reaches its normal position, the counting circuit is again closed from positive potential at the make contacts of relay II I, through the upper-middle pair of make contacts of relay I08, the upper make contacts of relay H2, the upper-break contacts of relay I I4, conductor I6I, the wiper and normal bank contacts of bank I5I, the lower contacts of relay I09, the lower make contacts of relay II2, the lower break contacts of relay H4, and the winding of relay II5 to negative potential. The relay II5 thereupon energizes, and upon the release of relay I09, due to the opening of the off-normal springs ONS, counting relay II4 energizes in series with relay II5 to positive potential supplied to it through the lower contacts of relay I06. Relay I I4, upon energizing, at its upper contacts transfers the marking circuit: from the conductor IGI associated with bank I5I to conductor I62 extendr ing to the wiper associated with the second-digit bank I52. The relay I08 now energizes over the circuit extending from it through the upper make contacts :of relay II2, the upper make contacts of relay II 4, the upper break contacts of relay II6,'the conductor I62, through the wiper and the tenth contact of bank I52 when the wiper reaches this contact. This bank contact having had positive potential put on it by the tell-tale relay 6I8. The sender now returns to normal in the manner hereinbefore described. When the sender reaches its normal position, the counting circuit will cause the operation of relay I H, from 2,008,910 the positive potential supplied through the con tacts of relay 1 by way of the upper-make contacts of relay H2 and ".1I'4,'theupper break contactsof relay 116, conductor 16.2, the wiper and normal contact of lbank152,the lower make contacts of relay 109, and the-lower make, contacts: of -relays1l.2 and 1, respectively, through the winding; of relay 1H and negative-potential. The relay 1l6 energizesin-series with the-relay I II in the same manner as did relays 1 I2 and-1l4, following thedeenergization of slow-release relay 109.. The relay 1 I6, upon operating, at its uppermost contacts transfers the marking circuit from the conductor 1.62 extending toithe wiperofbank 152 to the-conductor-163 ,extendingto the wiper of the third-digit;bank 153, at its lowermost make, contacts .extends the counting circuit to therelay Ila-and atyits inner-upper contacts prepares a ci'rcuitfortherelay-101. Relay-1H now releases and unlockszthe relay 108.=- i q Consequentto the closing of theinner-up'per contacts of relay 108, the sender begins sending the third digit of thecode. :Assoonas the off-' normalsprings ONS close, relay 109.energizes in the usual manner and closes acircuit from. positive potential atits upper contacts'by way of, the

' ing circuit is also extended; to relay 1 I; which; is

now energized, so that the locking circuit ofrelay 108 is dependent upon the release of relay 106,

since relays H0 and 1| I are at this time locked through contacts of relay 106; I 4 a I The-marked contact will now be found as the.

' first 'contactin the third-digit bank -1ss.-, The

relay 108 will, accordingly, energize ibypositive' potentialextende'd by way ;of the first contact in the third-digit bank 153 and its associated wiper, conductor 163, the upper make contacts of relay 1 l6,. and through the upper. make contacts of 'relays 1| 4 and H2, respectively, tothe winding of relayv 108 and negative potential; I ,Whenthe sender returns to normal, consequent to the closing of the'upper contacts of relay .108,'thecounting' circuit, from positive potential on the contacts of relay 1| 1, now extends by Way of the wiper and the normalcontact of the third-digit bank 153 and through the lower make contacts of relay 109,

energizes and atzits. upper contacts completes a lockingcircuit for itself extending through the lowermostcontacts of relay-106; The code is now complete, andthe code 10I has been sent to the I field, by the sender;

, of reset relay 604. This relay, upon operating, at

its lower pair of contacts closes ,the, circuit of relay 603, which-inturnenergizes to prepare the circuit of relay 602, andat its upper pair of contacts closes a circuit for. relay Gil-which is independent of thecontactsof relay 613 and places positivepotential on theire'set common conductor 630 extending to the tell-tale relay group TTR', The positive potential from the upper contacts of relay 604 passes by way of theinner-lower contacts of'relay 6l8-to the lower'winding of relay 6l9 andnegative potential. The relay 6|9 will, therefore, energize and lock-up to the upper contact of the. first operate key, and will open the operating circuit of the tell-tale relay H8 at its upper contact. This operation will, however, be withoutetfect at this time. l.

Thepreviously mentioned break at the endof the cycle), which was effected by the energization of relay 1 I8 opens the locking circuit of relay 610 of the miscellaneous relay group.- Relay 6l0, upon deenergizing, at its lowermost contacts closes a pointinthe line circuit, at its inner-lower contactsopens its 'ownlocking circuit, and at its uppermost contacts" opens the circuits of relays 6H and 6I3-." As aresult of the latter function, relay- 6I3 releases,;but.without effect, since the relay 6Il,is being maintained energized over the previously-mentioned circuit including the upper contacts \of-reIay -GM. The relay 6I,l, upon d6 energizing; however, opens the circuit of relay 6 I 2, which in turn removes positive potential from the start lead 6,29, thereby bringing about the release 1 of relays 104,;105, an d -106, respectiv ely. h relay ,the. sender, upon deenergizing; opens the locking circuit of relay 101, and of relays ;1l0 to 118', respectively, which accordingly restore the ,s'ender completely to normal. relay1I; I upon restoring, also opens the locking circuit of relay 108 so that this relay also restores. Relay 118, upon deen'e'rgizing, at its lowermost contacts opens the circuit of the miscellaneous relay 604. This latter relay, upon deenergizing, at its upper contacts removes positive. potential from the reset common conductor-6,30,, of the telltale relay,- at these same'contacts opensthecircuit of relay 6| 4, and atits lower contacts'removes positive potential from the lower: terminal of relay 603. l i i As a'result or the, last mentioned function, the relay, 602 is permitted to energize and lock-,up in serieswith the relay 603 to positive'potential sup plied byway of the make contacts of relay H5. The relay 602, upon energizing, at its upper contacts removes negative potential from the locking circuit'forr'nerly including the tell-talerelay BIB and the miscellaneous relay 60!, and these relays accordingly deenergizeu The miscellaneous relay 6 also deenergizes, as a result of the deenergization of relay 604, and will accordingly openthe circuit'of the relay 6l6. After ashort interval the relay 6l5 becomes deenergized, and performs the following function: at its lowermost contact reclosesthe #1 line, and at itsupper contacts opens the locking circuit of relays 602; and 603. f

The reclo'sing of the. #1. line causes themenergization of the line relay 601 at the dispatchers station, as well as oi'the, line relays201 of all field stations. The reenergization of the dispatchers line relay ,601' causes the release of the miscellaneous relays609 and 609. The relay 609, upon deenergizin'g, removes positive potential from the hold conductor 626 extending to the in comingsel'ector IS, and, accordingly, the counting relays formerly locked up thereto will also be deenergized.' 1,

The restoration of the miscellaneous relays 60I and 6,02jrestore' the supplyof the negative poten-' tial' to the'tell-tale relay pick-,up conductorf 620,

andth'eidispatchers circuits are now entirely at normal.

Additioncfitell-Jal relay'operdtions If it so happens'thatgother operate keys are also. operatedby the dispatcher, previous to the completion of a code, the 'foregoingoperations will-be repeated, anewtell-tale relay comingup Theeach time miscellaneous. relay 602-restores tits operate key that has changed position, the telltales coming up in succession, in the. order of their nearness from the circuit standpoint, to the miscellaneous relay Gill.

P It may be well to mention here thatany number of keys may be operatedin rapid succession, or'simultaneously, without in any way-affecting the order of the function of the equipment. A

- single key may even be operated maliciously back and forth, any number oi'times, but when the last code has been sent and the last code received, the signals on the dispatchers board will check with the final position of their operate keys, and the final position of the associated equipment in the field. This is true because the code registe'ring tell-tale relay, upon -operating,"is freed of control by the key until the code'initiated by its operation has been completely transmitted, and for the further reason that the other code registering relay of the same key operating circuit held open by the 'relay- BDI 'until the ini ti'ated code has been fullytransmittedi The same holds true for automatic signals from the field.

I l From the fleldoperation 7 Since the total number of from the field indicationswill probably always exceed one-hundred, it has beennecessary to provide an incoming selector IS which will respond to the first digit, and direct the remaining digitsto theproper connector switch, such as Di; These connector switches consist of a mechanism only, there being no relays required. I r f In the process of afield station seizing the line, it will be'remembered that the line was opened; When this happens,'of course, the dispatchers line relay 601 will fall away and cause the associated miscellaneous relays 60B and 609'to operate, and prepare the circuit'toth'e incoming selector IS. e

When the field station sends'the preliminary pulse over the line, line relay 601 of the miscellaneous relay group will energize momentarily and close the circuit of'relays llll and Il I of the incoming selector by way of theinner-upper make contacts of relay 609, the operate conductor 21, the lower break contacts of relay ell to the point I" where thecircuit branches, one branch passing direct to the relayllll and negativepo tential, while the other branch extends by way of the lower break 'contactsof relay 8M, and the upper break contacts ofrelay M2 to the winding of relay, 8H and negative potential. The relay 8M, upon energizing completes the energizing circuit of relay "1. This. latter relay, upon energizing, at its lowermost contacts completes a circuit by way of the upper-break contacts of relay, 804 for the relay 803." At the end of the pulse, relay 8 becomes energized inserles with relay 803 from positive potential supplied through the lowermost contacts of the relay II I. The relay BIN, upon operating, at its lower break springs open the pulsing circuit to'the counting relays lll to Ill, inclusive, and at the lowerinake'contacts closes a circuitto the motor magnet iii of the incoming selector by way of the lower-make contacts of relay "2, thelower break contacts of relay 8, and the lower break contacts of relay 806, respectively The relay 804 also at its upper make contacts extends its own counting circuittorelay "I; s

,It will be assumed'that the field sends the code I. The line relay 601 will, accordingly, momentarily energize once in response to the first digit, and will send one pulse to the magnet transfers the operate conductor from the motor magnet III totheconductor: llf.

The line relay "1 will" now momentarily energize three times inresponse'to the secondv digit of the code. and will'send three pulses to the vertical magnet of the first connector over the puls-- in'g'circuit by way ofz'the lower make contacts of relay I, the lower make contacts of relay Oil, the lower break contacts of relay-Ill, theiiower make contacts of relay I. conductor-Ill, the

lower break contacts of relay I, the wiper Ill 0!- the incoming selector and its first bank contact, and the conductor I" to the vertical magnet and negative battery of'the first connector D, thereby elevating the wiper of thisconnector opposite the third row or level of its bank contacts. Consequent to the transmission of the second series of impuisethe relays "I and I again become energized and also complete a circuit for the counting relay 801. Accordingly, following the transmission of the second digit relays .III and I02 again deenergize with theresult that the relay Ola-becomes energized in series with the relay 801. The relay Ill, upon energizing. transfers the counting circuit tothe relay "land at its lower "contactstransfers the operate 'circuit from the connection to the vertical magnet of the connector D'- to the wiper I, which is connected with the conductor 8" extending to the rotary magnet of the connector.

The line relay "1 .will now'momentarily. energize four times in' response to the third digit of the code'and will send four pulses over the previously traced circuit toconductor I, through the lower front contacts of why I, the wiper I" and its first bank. contact. conductor lllto the rotary magnet of*the connector, which will accordingly rotate its wiper 525 into engagement with the fourth bank contact in thethlrd level of its bank; During the trion of the third digit of the code, relays. and "2 again energize andthe relay "2 'in'turn completes the circuit of counting relay "8. Accordingly, at the termination of the third digit therelays Ill and I02 again become deenergized with the result that the relay Ill becomes energized in series with the relay I. The relay I", upon operating, at its upper contacts opens the counting circuit, and at its lower contacts also opens the operating circuit.

As previously-mentioned, the wiper of the first connector has now been brought into engagement with its thirty-fourth bankcontact. As a further result of the deenergization of relay III, following thetransmission of the last digit, a circuit is now closed from positive potential through the lower contacts of relay I, wiper conductor "8, the break contacts of relay Ill, conductor 855, the connector wiper "I, the thirty-fourth-bank contact of the connector, and the return-indication polar relay winding I" to negative potential. The armature of the polar relay, accordingly, moves over to they left. thus extinguishing its green lamp 6 and lighting the red lamp R. as an indication that the represented customer's relay' has changed to-the correspond ing position in the field.

' Upon the completion of the code'i'rom the field, the line againremains'closed, whereupon all the line relays again become energized. When the dispatcher's line'relay 601 again remains energized theassociated miscellaneous relays Bil! and "9 become deenergized; Asaresultof this, the hold circuit isopened-at the upper contacts of relay "9 and, accordingly, relays 8 tot, inclusive, of the "incoming selector IS, becorne. deenergized. Upon the deenergization oi relay ill the holding circuit for the countingrelays I to Ulil, inclusive, is also opened, with the result that these relays also become deenergized. The relay 600 also; upon becoming deenergized, at its inner-upper'contacts supplies positive potential, through the make contacts of line relay 'L'to the release conductor 628, through the off-normal springs 0N2, oi the incoming selector" to the release magnet BIB thereof and negative potential, and-also byway of the oft-normal .springs CNS of the connector D to the release magnet of this connector. As a result of this, the incoming selector and the connector will restore in a wellknown manner, and at their oil-normal springs open their release circuits upon the'com pletion of the release operation.

D ispotchers lockout In case afield station is using the line, the dispatcher's station is locked out, because of its miscellaneous relays-608 and 609 being in their operated positions. This prevents the closing of the circuit of relay 605 even though the relay I becomes 'operated,'-and therefore, the dispatchers circuits cannot function.

Simultaneous dispatcher and field operation In certain instances it may occur that a field station and the dispatchers station both open the line at the same time. In such an event the field station is lockedout by virtue of thefact that the line is opened at the dispatchers station.

I Since the line is 'openedat the dispatchers station, the field station preliminary pulse is without eflect on the line, and'the field miscellaneous relay circuit restore, as previously explained un der simultaneous field operation.

Since the line is alsoflcpened at the field station it is important that the dispatcher's sender does not start sending until the field circuits have been completely restored to their waiting position. This is the reason for the provision of delay relaysiiil and ii! of the dispatchers miscellaneous relay group and of relays l0 and 1" otthe'se'nder. 'These relays also allow a suili cient time interval between the seizing of the line and the start of the code to permit any field station which mayhave seized simultaneously to get into the clear, and restore its miscellaneous relay 2".

Automatic indication The indications from the field stations may be divided into two classes, first, indications which return as the result of an operation brought about by the dispatcher, and second, automatic indications which occur as the result of some change in the field not originated by the dispatcher.

This latter type of indication is required in railroad practice to give a train dispatcher an indication of a train having run in on a siding, and is commonly known as on 0. S. indication. It sometimes is desired that an indication of this character be Zlocked", even though the change" in the field is-only momentary, To accompllsh this the lock-in key K is provided on the dispatcher'sboard. i It may also be desirable, in certain instances, to obtainia printed record'of the time of operation in'making this automatic indication. This is arranged for by' the provision-of pairsoi' relays 50! and! placedintermediate to the contacts on the automatic indication polar relays and their indicating lamps.

-'It-will be assumed "that a iromthe field" code causes the Jfirst connector to position its wiper upon itseleventhcontact and thereby causes the automatic indication polar relay winding 528 to move the associated armature to the right. The relay 502, accordingly, becomes deenergized. With-the armature of winding 528 in its= new position a circuit is completed to the slow-tooperate relay 501. Since this relay 'is slowtooperate a continuationof the circuit momentarily extends through its-break contacts to the printer and back through the break contacts of relay 502 and the winding of this relay to'negative potential. The printer will, accordingly, operate and, after a delay, the relay Sill willthen operate and open the circuit oi. the printer, and at its iipper contacts close the circuit of the associated amp. I

If the locking'ke'y K is in its operated position the relay 5!" remains locked up, instead of becoming deenergized when the polar relay again station, a field station, a line connecting said stations, a movable device at said field station, means for moving said device, a relay having a single winding and a make-beiore-break contact combination, anoperati'ng circuit for said relay closedconsequent to the movement of said device and including said winding and the break contacts of said combination, a locking circuit for said relay closed by its operation including said winding and the make contacts 0! said combination, a second relay'included in said locking circuit and energized in response to the closure of said locking circuit, a sending switch for trans mitting pulses over said line, set into operation by said second relay, means controlled by said first relay for determining the code transmitted by said sending switch, equipment at the dispatchers station responsive to said pulses to reg ister the change in position of said device, means associated with said sending switch for interwipers for controlling said pieces of equipment, a transmission line with. which said connectors are associated, means located at a remotepoint for impressing control signals on said line, means responsive to such signals to position the wipers of one of said connectors into connection with a desired piece of equipment and to operate it, indication transmitting apparatus controlled by the device operated to impress indication control pulses on said line, code switches at the remote point responsive to said pulses to indicate a change in position of the equipment, means for always transmitting a single preliminary pulse over said line preceding the transmission of an indication signal thereover, means responsive to said preliminary pulse to lockout and prevent a control signal being sent out while indication pulses are being transmitted, means for always transmitting a plurality of preliminary pulses over said line preceding the transmission of a control signal thereover, and means responsive to said preliminary pulses to lockout and prevent indication impulses being sent thereover while control impulses are being transmitted.

3. In a dispatching system, a dispatchers station, a plurality of field stations, a line connecting said stations in serial relation, pieces of equipment at each field station, a code responsive switch at each field station having access to its pieces of equipment, an operating circuit associated with eachof said switches, position indicating control means at the dlspatchers station for each of the respective pieces of equipment at the field stations, a code responsive switch at the dispatcher's station having access to said control means, means at the dispatchers station for transmitting a plurality of preliminary pulses to said line, a controlling relay at each field station included in said line and responsive to all impulses transmitted thereover; an operating circuit at each station for its code responsive switch; means at each field station responsive to the operations of its controlling relay, when responding to a plurality of preliminary pulses, to prepare theoperating circuit of its associated switch; means at the dispatchers station for then trans mitting a code over said line to,.actuate said con-f trolling relays and through one of them position one of said switches into connection with the piece of equipment represented, means operated consequent to a change in the position of a piece of said equipment for transmitting a single preliminary pulse over said line, means responsive. to such pulse to prepare the operating circuit of the dispatchers code responsive switch to the exclusion'of the code responsive switches of the field stations, and means for then transmitting a code of impulses to said switch to select and operate the indicating signal of the repositioned piece of equipment in the field.

4. In a selective signalling system, a dispatchers station, a plurality of remote stations, a line circuit joining the stations including a line relay at each station and a source of current supply, units of equipment at each remote station transmitting means in the remote stations for transmitting over said line circuit, normally inoperative selecting means insaid remote stations for selecting said units, means at-thedispatchers station for transmitting a code of impulses over the line in all instances including a pair of preliminary lockout impulses followed by a plurality of series of selecting impulses, means in the remote stations responsive to the lockout impulsesof the code for lockingout the transmitting means ateach remote station to prevent transmission therefrom and for rendering said selecting. means operative to receive the selec ingimpulses of the code, and means thereaftsg responsive to the selecting impulses oi! the cod, for operating said selecting means to select and operate a particular unit at one of said stations. ,5. In a selective signalling and remote control system, a dispatcher's station and a plurality of remote stations joined by a line circuit, devices at the remote stations and the dispatcher's station, selecting means at each station for selecting a particular device, a code sender at each remote station for transmitting a code of pulses over. the line circuit to select a device at the dispatchers station, means in said sender always transmitting a preliminary pulse over said line; means at other of the remote stations, responsive thereto to lock out such other of 'the remote stations, means at the dispatchers station responsive thereto to render the selecting means at the dispatchersstation operative, a code sender at the dispatchers station, means in said last sender for always transmitting a pair of preliminary impulses, said previously specified preliminary impulse responsive means operating in response thereto to render the selecting means at the dispatcher's station inoperative and the selecting means of theremote stations operative.

6. In a selective signalling system, a dispatchers station, a plurality of remotestations, a line circuit joining the stations, units of equipment atv each remote station, means at the dispatcher's station for transmitting a. code of impulses over the line circuit in all instances including a pair of preliminary impulses followed by a plurality or series of selecting impulses, selecting means in the remote stations for selecting and operating.said units, said selecting means at all said remote stations normally inoperative, means in the remote stations responsive to said preliminary impulses of the transmitted code for rendering all said selecting means operative, and ,means thereafter responsive to the selecting impulses of the transmitted code for operating said selecting means at all said stations to select and perate a particular unit atonly one of said stations.

HARRY E..HERSHEY, ALFRED H. BELLIVEAU. 

